$\dfrac{4}{5} \div \dfrac{9}{2} = {?}$
Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $\dfrac{9}{2}$ is $\dfrac{2}{9}$ Therefore: $ \dfrac{4}{5} \div \dfrac{9}{2} = \dfrac{4}{5} \times \dfrac{2}{9} $ $ \phantom{\dfrac{4}{5} \times \dfrac{2}{9}} = \dfrac{4 \times 2}{5 \times 9} $ $ \phantom{\dfrac{4}{5} \times \dfrac{2}{9}} = \dfrac{8}{45} $